use English qw($CHILD_ERROR);
use XML::Simple;

# If a fast parser for XML::Simple is installed, then use it.
my $parser = 'XML::LibXML::SAX';
my $cmd    = "perl -M$parser -e 1";
my $output = qx($cmd 2>&1);
unless ($CHILD_ERROR) {
    $XML::Simple::PREFERRED_PARSER = $parser;
}